Apple revises its Podcaster Tech Specs document to provide information on Apple TV compatibility.

Although I haven’t published an episode for a while, I am a podcaster. My Maria Speaks podcast has about 30 episodes published over the past two years or so.

Because of that, I’m on Apple’s mailing list for information about podcasting. And today I got an e-mail message from Apple that provides some useful information about formatting video or enhanced podcasts for better compatibility with Apple TV.

Here’s part of it:

Recommendations for Formatting Video Podcasts

1. If you’re encoding your video podcast at 320×240, please increase the resolution to either 640×480 or 640×360 (depending on the aspect ratio of your source files). Why? Because video podcasts at this resolution look great on Apple TV and still port to video iPods. Lower resolution podcasts might also work on both platforms, but they don’t look nearly as good on a widescreen TV. As always, make sure to test any encoding changes you make to ensure device compatibility. QuickTime 7.1′s “Export to iPod” function will ensure that a video file is encoded at a width of 640 and is iPod-compatible.

2. It’s best not to create two different podcast feeds for different resolutions. By doing so, you dilute the popularity of your podcast and reduce exposure in our charts. It’s better to have one feed high in the charts than two that are lower.

3. If your source files are 16:9, stick with that aspect ratio. Don’t add letterboxing to make them 4:3. By doing so, you prevent the video from expanding to fill a 16:9 widescreen TV and instead end up with black space on all four sides. Also, your original source files should be at least 640 pixels wide.

Of course these are just recommendations. We understand that there are good reasons for 320×240 (bandwidth bills) and 720p (looks fantastic). Do whatever makes the most sense for your show. For more information on formatting video, see the recently updated spec:

http://www.apple.com/itunes/store/podcaststechspecs.html

To see a sample of excellent podcasts that also look great with Apple TV, check out the Apple TV Podcast Showcase.

This is interesting because one of the few complaints I’ve heard about Apple TV is the video quality of podcasts. It appears that Apple is trying to prevent this from being a problem by providing podcasters with detailed instructions for making their podcasts look good on Apple TV.

I do a “video” podcast for Flying M Air called Come Fly with Us! It’s basically an iMovie slide show of images taken on various flights and day trips throughout Arizona. Although I don’t want to go back and fix existing episodes so they meet these requirements, I’ll probably release new episodes with these specs on a go-forward basis.

As mentioned by Apple in the quoted e-mail above, a higher resolution will lead to bigger files. Not only will this affect bandwidth, but it can discourage potential subscribers from subscribing. For example, since moving from my downtown office back into my house, my download speed has been cut from high-speed DSL (5-7 M) to medium speed cable (512 K if I’m lucky). A 70 MB podcast has to be pretty darn good for me to further slow down my Internet access speed with a lengthy download. Right now, each episode of Come Fly with Us! is about 15 MB; I’m curious to see what the higher resolution files will be.

Just something to keep in mind.